Disk drives for storing electronic information are found in a wide variety of computer systems, including workstations, personal computers, and laptop and notebook computers. Such disk drives can be stand-alone units that are connected to a computer system by a cable, or they can be internal units that occupy a slot, or bay, in a computer system. Laptop and notebook computers have relatively small bays in which to mount internal disk drives and other peripheral devices, as compared to the much larger bays available in most workstation and personal computer housings. The relatively small size of peripheral bays found in laptop and notebook computers, can place significant constraints on the designer of internal disk drives for use in such computers. Techniques that address and overcome the problems associated with these size constraints are therefore important.
Disk drives of the type that accept removable disk cartridges have become increasingly popular. One disk drive product that has been very successful is the ZIP.TM. drive designed and manufactured by Iomega Corporation, the assignee of the present invention. ZIP.TM. drives accept removable disk cartridges that contain a flexible magnetic storage medium upon which information can be written and read. The disk-shaped storage medium is mounted on a hub that rotates freely within the cartridge. A spindle motor within the ZIP.TM. drive engages the cartridge hub when the cartridge is inserted into the drive, in order to rotate the storage medium at relatively high speeds. A shutter on the front edge of the cartridge is moved to the side during insertion into the drive, thereby exposing an opening through which the read/write heads of the drive move to access the recording surfaces of the rotating storage medium. The shutter covers the head access opening when the cartridge is outside of the drive, to prevent dust and other contaminants from entering the cartridge and settling on the recording surfaces of the storage medium.
The ZIP.TM. drive is presently available for workstations and personal computers in both stand-alone and internal configurations. In order to provide a version of the ZIP.TM. drive for use in laptop and notebook computers, the size constraints of the peripheral bays of such computers must be considered. In particular, for an internal drive to fit in the majority of laptop and notebook peripheral bays, the drive must be no longer than 135 mm. The height of the drive must be in the range of 12 to 15 mm. These dimensions place many constraints on the design of such a drive, and give rise to numerous design problems. The present invention addresses and overcomes some of the problems presented in designing a disk drive to these specifications.
A disk drive typically includes an actuator that has heads for interfacing with a disk cartridge, a head retraction system for moving these heads to a retraced position, an eject system for ejecting a disk cartridge from the disk drive and an operating system for powering the head retraction system and the eject system. By way of background a general overview of the operation of a disk drive employing these features is provided.
A disk cartridge is inserted into the disk drive. In order to remove the disk cartridge from the drive, an eject button disposed on the periphery of the drive is typically depressed. This button causes the operating system to power the head retraction system. When powered, the head retraction system causes the heads to move away from the disk cartridge and into a retracted position. After the heads have been retracted the operating system powers the eject system and ejects the disk cartridge from the disk drive.
Due to the limited length and height of a disk drive designed to be incorporated into a lap top computer, each of these systems must operate in a relatively small volume. Furthermore, many of the known prior art systems cannot be integrated into a disk drive having these limitations. While the eject system, head retraction system, operating system and motor loading system are advantageous for their intended applications, there is a need for improved systems that can be implemented in lower profile disk drives, such as that described above. The present invention satisfies these needs.